JP6807895B2 - Welding method for square steel pipe - Google Patents

Description

According to the present invention, a method for welding square steel pipes, particularly, when connecting square steel pipes to existing square steel pipes facing each other at intervals and connecting the existing square steel pipes to each other, it is not necessary to support the connected square steel pipes. The present invention relates to a method for welding a square steel pipe, which has a short welding length and does not require a backing metal to be attached to the outer surface of the end of the square steel pipe.

An example of a welding method for a square steel pipe is disclosed in Patent Document 1. Hereinafter, this welding method is referred to as a conventional welding method, and will be described with reference to the drawings.

FIG. 3 is a partial front view showing a square steel pipe before welding by the conventional welding method, FIG. 4 is a sectional view taken along the line AA of FIG. 3, and FIG. 5 is a partial front view showing a square steel pipe after welding by the conventional welding method. , FIG. 6 is a cross-sectional view taken along the line BB of FIG.

Square steel pipes are welded to each other by the conventional welding method as follows.

First, as shown in FIGS. 3 and 4, a notch 12 is continuously formed in the upper end of the double-sided steel pipe 11, and the lower end of the double-sided steel pipe 11 in which the notch 12 is not formed is formed. Butt and weld the bottom of this end to join. When welding the lower end of the double-sided steel pipe 11, a backing metal 13 is attached to the outer surface of the lower end, and the closing member 15 described later is welded to the inner surface of the upper end of the double-sided steel pipe 11. The backing metal 14 required for this is attached in advance.

Next, as shown in FIGS. 5 and 6, a closing member 15 formed in the same shape as the cutout portion 12 is fitted into the notch portion 12 continuously formed in the square steel pipe 11 to close the square steel pipe 11. The member 15 is welded and joined.

As described above, the square steel pipes 11 are welded to each other via the closing member 15.

Japanese Unexamined Patent Publication No. 7-292781

According to the above-mentioned conventional welding method, the square steel pipes 11 can be welded to each other without performing upward welding, but as shown in FIG. 7, existing square steel pipes fixed to face each other with a space between the columns 16 When the connecting square steel pipe 18 is welded to the 17 and the existing square steel pipes 17 are connected to each other, there are the following problems.

(A) In order to prevent the connecting square steel pipe 18 from falling during welding, it is necessary to support the connecting square steel pipe 18 by some means, so that the welding operation cannot be easily performed.
(B) Since the closing member 15 is used, the welding length becomes long, and the welding work takes time accordingly.
(C) Since the backing metal 13 needs to be attached to the outer surface of the lower end of the double-sided steel pipe 11, the outer surface of the square steel pipe 11 becomes uneven, which is not preferable in terms of appearance and function.

Therefore, an object of the present invention is that when connecting square steel pipes to existing square steel pipes facing each other at intervals and connecting the existing square steel pipes to each other, it is not necessary to support the connected square steel pipes, and the welding length is reduced. It is an object of the present invention to provide a method for welding a square steel pipe, which is short and does not require a backing metal to be attached to the outer surface of the end of the square steel pipe.

The present invention has been made to achieve the above object, and is characterized by the following.

The invention according to claim 1 is a method for welding a square steel pipe, in which a connecting square steel pipe connecting the existing square steel pipes is welded to the existing square steel pipes facing each other at intervals. The existing square steel pipe of the existing square steel pipe is used. The end portion is cut out in a stepped manner so that the lower portion of the existing square steel pipe end portion protrudes forward, and the connecting square steel pipe end portion of the connecting square steel pipe is projected forward by the upper portion of the connecting square steel pipe end portion. as notched stepped, the existing mounting a backing strip for existing RHS of the upper inner surface of the square tube ends are formed in a U-shape, U-shape at the bottom inner surface of the connecting square tube end It is characterized in that the formed backing metal for connecting square steel pipe is attached, the connecting square steel pipe is fitted within the space, and the existing square steel pipe end portion and the connecting square steel pipe end portion are welded and joined. It has.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the existing square steel pipe connected by the connecting square steel pipe is a beam fixed between columns.

According to the present invention, when connecting square steel pipes to existing square steel pipes facing each other at intervals and connecting the existing square steel pipes to each other, it is not necessary to support the connected square steel pipes by some means.

Further, according to the present invention, since the closing member is not used unlike the conventional welding method, the welding length is shorter than that of the conventional welding method.

Further, according to the present invention, since it is not necessary to attach the backing metal to the outer surface of the end portion of the square steel pipe, the outer surface of the square steel pipe is not uneven.

It is a partial perspective view which shows the square steel pipe before welding by the welding method of the square steel pipe of this invention. It is a partial perspective view which shows the square steel pipe after welding by the welding method of the square steel pipe of this invention. It is a partial front view which shows the square steel pipe before welding by the conventional welding method. FIG. 3 is a sectional view taken along the line AA of FIG. It is a partial front view which shows the square steel pipe after welding by the conventional welding method. FIG. 5 is a sectional view taken along line BB in FIG. It is a front view which shows the state which existing square steel pipes were welded to each other through the connecting square steel pipe by the conventional welding method.

An embodiment of the method for welding a square steel pipe according to the present invention will be described with reference to the drawings.

FIG. 1 is a partial perspective view showing a square steel pipe before welding by a method of welding a square steel pipe of the present invention, and FIG. 2 is a partial perspective view showing a square steel pipe after welding by a method of welding a square steel pipe of the present invention. is there.

In FIGS. 1 and 2, reference numeral 1 denotes existing square steel pipes facing each other at intervals. The existing square steel pipe 1 is horizontally fixed so as to face each other with a space S between columns (not shown). The existing square steel pipe end portion of the existing square steel pipe 1 is notched in a stepped manner so that the lower portion 1a of the existing square steel pipe end portion projects forward.

Reference numeral 2 denotes a connected square steel pipe that connects the existing square steel pipes 1 to each other to construct a beam or the like. The upper portion 2a of the connecting square steel pipe end portion of the connecting square steel pipe 2 is notched in a stepped manner so that the connecting square steel pipe end portion protrudes forward.

Reference numeral 3 denotes a backing metal for the existing square steel pipe attached to the inner surface of the upper portion 1b of the end portion of the existing square steel pipe. The backing metal 3 for the existing square steel pipe is formed in a U shape, and is attached to the inner surface of the upper portion 1b of the end portion of the existing square steel pipe slightly protruding from the upper portion 1b and downward.

Reference numeral 4 denotes a backing metal for the connecting square steel pipe attached to the inner surface of the lower portion 2b of the end of the connecting square steel pipe. The backing metal 4 for the connecting square steel pipe is formed in a U shape, and is attached to the inner surface of the lower portion 2b of the end portion of the connecting square steel pipe slightly protruding from the lower portion 2b and upward. When welding the existing square steel pipe 1 and the connecting square steel 2, the lower part of the backing metal 3 for the existing square steel pipe and the upper part of the backing metal 4 for the connecting square steel pipe overlap in the vertical direction (see FIG. 2). ..

According to the method for welding a square steel pipe of the present invention, a connecting square steel pipe 2 for connecting the existing square steel pipes 1 is welded to the existing square steel pipes 1 facing each other at intervals S as follows.

As shown in FIG. 1, the end is notched in a stepped shape, and the end is stepped at the interval S of the existing square steel pipe 1 to which the backing metal 3 for the existing square steel pipe is attached to the inner surface of the upper end 1b. The connecting square steel pipe 2 is fitted into the inner surface of the lower end portion 2b to which the backing metal 4 for the connecting square steel pipe is attached.

Then, the existing square steel pipe end and the connecting square steel pipe end are completely melted and welded to be joined.

At this time, the lower portion 1a of the end of the existing square steel pipe and the upper portion 2a of the end of the connecting square steel pipe come into contact with each other, and the backing metal 3 for the existing square steel pipe and the inner surface of the upper portion 2a of the end of the connecting square steel pipe come into contact with each other. Since the backing metal 4 for connecting square steel pipes and the inner surface of the lower portion 1a of the end of the existing square steel pipes come into contact with each other, it is not necessary to support the connecting square steel pipes 2 by some means when connecting the existing square steel pipes 1.

Moreover, since the closing member is not used unlike the conventional welding method, the welding length is shorter than that of the conventional welding method.

Further, since it is not necessary to attach the backing metal 3 for the existing square steel pipe and the backing metal 4 for the connecting square steel pipe to the outer surfaces of the ends of the existing square steel pipe 1 and the connecting square steel pipe 2, the backing metal 3 for the existing square steel pipe and the backing metal 4 for the connecting square steel pipe 2 The outer surface of the backing metal 4 for the connecting square steel pipe is not uneven.

As described above, according to the present invention, when the connecting square steel pipes 2 are welded to the existing square steel pipes 1 facing each other at intervals S, and the existing square steel pipes 1 are connected to each other, the connecting square steel pipes 2 are connected. Welding work can be easily performed because it does not need to be supported by any means.

Further, according to the present invention, unlike the conventional welding method, a closing member is not used, and only the existing square steel pipe 1 and the connecting square steel pipe 2 are welded, so that the welding length is shorter than that of the conventional welding method. Therefore, the welding work time is shortened.

Further, according to the present invention, since it is not necessary to attach the backing metal 3 for the existing square steel pipe and the backing metal 4 for the connecting square steel pipe to the outer surfaces of the ends of the existing square steel pipe 1 and the connecting square steel pipe 2, the existing square steel pipe The outer surfaces of 1 and the connecting square steel pipe 2 are not uneven, which is preferable in terms of appearance and function.

1: Existing square steel pipe 1a: Lower part of existing square steel pipe end 1b: Upper part of existing square steel pipe end 2: Connecting square steel pipe 2a: Upper part of connecting square steel pipe end 2b: Lower part of connecting square steel pipe end 3: Existing square steel pipe Backing metal for steel pipe 4: Backing metal for connecting square steel pipe 11: Square steel pipe 12: Notch 13: Backing metal 14: Backing metal 15: Closing member 16: Strut 17: Existing square steel pipe 18: Connecting square steel pipe

Claims (2)

In a method for welding a square steel pipe, which welds a connecting square steel pipe that connects the existing square steel pipes to existing square steel pipes that face each other at intervals.
The existing square steel pipe end of the existing square steel pipe is cut out in a stepped manner so that the lower part of the existing square steel pipe end protrudes forward, and the connecting square steel pipe end of the connecting square steel pipe is cut out at the connecting square steel pipe end. A stepped notch is made so that the upper part of the portion protrudes forward, and a backing metal for the existing square steel pipe formed in a U shape is attached to the upper inner surface of the existing square steel pipe end portion, and the connecting square steel pipe end portion is attached. A backing metal for connecting square steel pipes formed in a U shape is attached to the inner surface of the lower portion of the steel pipe, the connecting square steel pipes are fitted within the space, and the existing square steel pipe end portion and the connecting square steel pipe end portion are connected to each other. A method for welding a square steel pipe, which comprises welding and joining. The method for welding a square steel pipe according to claim 1, wherein the existing square steel pipe connected by the connecting square steel pipe is a beam fixed between columns.

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